Release mechanism

ABSTRACT

This invention relates to a time-delay release mechanism for restraining and releasing large loads. For example, as in the case of a steel banding strap used to hold a large package together. The invention, in one embodiment, includes adjacent, rotatably mounted release levers which distally engage the ends of the strap at the mounting thereof. The release levers are connected by a rotatably mounted locking lever. In a second embodiment, a single release lever, adapted to engage one end of a fixed strap, is resiliently attached to a rotatable mounting by a locking lever. A timer selectively allows rotational movement of the locking lever to free, in one embodiment both release levers, and in the other, the release lever and the mounting, which in turn release the load.

0 United States Patent [111 00,7

[72] Inventor Ralph G. Eshleman 2,845,676 8/1958 Huber 24/201 DLancaster, Pa. 3,425,739 2/1969 Frost et a1 24/201 D X 969 PrimaryExaminer-Donald A. Griffin Attorney-Le Blanc and Shur [45 Patented Aug.24, 1971 [73 l Assignee Hamilton Watch Company Lancaster, Pa.

ABSTRACT: This invention relates to a time-delay release 5 RELEASEMECHANISM mechanism for restraining and releasing large loads. For excm6 Drawing Fm ample, as In the case of a steel banding strap used to holda large package together. The invention, in one embodunent, um [52] US.Cl. 24/68 R, eludes adjacent rotatably mounted release levers which24/201 58/59 distally engage the ends of the strap at the mountingthereof. [5] I III!- Cl. ..A43C 11/14, The release levers are connectedby a rotatably mounted G041 33/00 locking lever. ln a second embodiment,a single release lever, {50! Fit 0 Search 58/59, 80; adapted to engageone end of a fixed strap is ili l av 24/68 CD68 SR'68 tached to arotatable mounting by a locking lever. A timer selectively allowsrotational movement of the locking lever to 1 References CM free, in oneembodiment both release levers, and in the other, UNITED STATES PATENTSthe release lever and the mounting, which in turn release the 2,497,4672/1950 Peters 24/68 CT .oad.

Patented Aug. 24, 1971 0 s Sheets-Sheet 1 INVENTOR RALPH G. ESHLEMANATTORNEYS Patented 1971 3 Sheets-Sheet 2 FIG. 4

INVENTOR RALPH G. ESHLEMAN ATTORNEYS Patented Aug. 24, 1971 3Sheets-Sheet 5 INVENTOR G ESHLEMAN ATTORNEYS RELEASE MECHANISM Thisinvention specifically pertains to time-delay release mechanisms,whereby a load is contained until a preset time elapses, and then, isreleased.

The prior art contains a variety of mechanisms including timers whichunlock release levers. Of note is US. Pat. No. 2,534,836 to R.I.I-Iakomaki. In the I-Iakomaki device, a cam on the timer displaces acatch which in turn releases a hook which rotates to disengage the loadcarried by the hook. The hook is used to release a high-altitudeballoon, and is not adapted to the particular problem of releasingpackage banding straps.

Prior art release mechanisms, including the Hakomaki device, have thedistinct disadvantage of requiring a timer output large enough toovercome a load acting through the release lever, on the lockingmechanism. For example, Hakomaki attempts to minimize the outputrequired from the timer by using overlapping rather than hooking-typelocking levers. However, a positive displacement of the locking memberby the timer to release the load is still required.

The release mechanism of this invention is designed to hold the two endsof a packaging strap. The ends of the strap engage abutting releaselevers which are held until a preset time elapses. The mechanism of thisinvention uses the incident load to release a locking lever, as comparedto the conventional means of using a timer output to drive the saidlever thereby releasing the load.

In the alternate situation wherein one end of the strap is fixed, one ofthe release levers is replaced with a rotatable latch which is locked inan abutting relationship to the free end of a single release lever.

Accordingly, it is an object of this invention to provide a timedrelease mechanism for holding the ends of the banding strap.

g It is another object to provide a simple and accurate releasemechanism having a timer for simultaneously releasing the ends of apackaging band.

It is a further object .to provide an elongated, pivotally mountedrelease lever adapted to transfer a negligible torque to the lockinglever, thereby eliminating the possibility of stalling the timer underthe load necessary to release the locking lever.

It is a further object to provide a release mechanism wherein the loadto be released normally urges the locking lever into the unlockedposition.

It is yet another object to provide a locking lever for a timedelayrelease mechanism wherein the load to be released normally urges a tabon the said lever into a slot on the rotating output shaft of the timerto displace the lever, and release the load.

It is still another object to provide a release lever pivotally mountedat an end thereof and adapted to engage a load at the pivotal mountingthereby transferring a nearly negligible torque from the load to thelever.

These and other objects will become apparent with relation to thefollowing drawings and description:

FIG. 1 is a front elevation in partial section of the first embodimentof this invention in a locked position;

FIG. 2 is a front elevation also partially in section of the embodimentof FIG. 1 showing the release position in phantom;

FIG. 3 is a front elevation partially in section of the secondembodiment of this invention;

FIG. 4 is an elevational view in partial section of the timingmechanism;

FIG. 5 is a perspective view of the embodiment of FIG. 1 and the timerwith the output shaft withdrawn from the timing mechanism; and I FIG. 6is a perspective view of the timer gear train.

With attention to'FlG. l, the first embodiment of this inventionfeatures right and left release levers 23 and 13, respectively. Theselevers are substantially Is-shaped, and, the particular advantages ofthis invention stem, in part, from their design.

Left release lever 13 is rotatably mounted on a base (not shown) at pin15. Pin 15 engages the upper portion of a vertical leg 17 on a nearlyhorizontal line with the load-engaging hook 19, on leg 17. Thus, themain force of the load from the strap 21 is carried by pin 15 whilelever 13 carries a nearly negligible counterclockwise moment imparted bythe load.

Right release lever 23 is rotatably mounted at the base at pin 25. Thevertical leg 27 of lever 23 similarly engages a load at hook 29. Theload from strap 31 is imparted to lever 23 on nearly a horizontal linewith pin 25.

The horizontal legs 33 and 35 of levers 13 and 23, respectively, areadapted to nest as shown in FIG. 1 touching only at pivot point 37. Inorder to minimize the torque from lever 13 transmitted to lever 23 therounded end 39 of leg 33 is designed so that a line normal to end 39 atthe pivot point 37 will extend through the pin 25 of lever 23.

Locking lever 41 rotatably mounted on the base at pin 43 exerts ahooking action on locking pin 45 of lever 23. When hooking portion 47 oflever 41 is engaging lever 23 as shown in FIG. 1, pin 45 is designed tobe in vertical alignment with the mounting pin 43.

It should be noted that the horizontal load applied in FIG. 1 to lever23 exerts a torque in a clockwise direction on lever 23 which istransmitted through locking 45 to locking lever 41. The load from thelever 13 is dissipated at pin 25, and therefore, the force exerted onlocking lever 41, the clockwise torque, tends to urge rotation of thelocking lever 41 in a clockwise direction about its mounting.

With attention to FIGS. 1 and 2, timer output shaft 51, having slot 53,acts as a stop for the clockwise rotation of locking lever 41. Key 55normally rides on the shaft 51 as it rotates until slot 53 registers onthe key, at which point, key 55 is urged into the slot by the clockwisetorque from release lever 23.

As shown in FIG. 2, movement of the key 55 into the slot 53 unlockslever 41 and frees lever 23 for rotation about pin 25 and lever 13 forrotation about pin 15, thereby releasing straps 21 and 31.

A primary purpose of this invention has been to develop a timed releasemechanism wherein the unlocking load requirement will not stall thetimer. As shown in the above description the design of the releaselevers dissipates nearly all of the load exerted on the levers at theirrespective mountings. This particular design allows the release ofextremely large loads with a very small timing mechanism.

In testing the mechanism of FIG. 1, a load of 1,125 pounds was appliedat strap 21 and a zero load at strap 31. The locking lever was thenremoved so that the left release lever 13 was restrained only by theright lever 23. The result was that the left lever exerted insufficienttorque on the right lever to force the right lever into rotation,allowing the left lever to release the load. This would indicate thatthe load on the left release lever is limited primarily by the integrityof the support and not by the timer output device.

Moreover, when both release levers are loaded, a constant force isexerted on the timer output shaft urging key 55 into slot 53. The timeroutput is not subject to a surge requirement to release the load. Ineliminating a surge requirement the possibility of a stall at release isalso eliminated. If stalling is to occur, the timer will stall when itis started, due to the force exerted by key 55 on timer output shaft 51.However, as pointed out, the device of this invention minimizes the loadcarried by the timer output shaft and maximizes the load carried by therelease lever mounting pins and support.

FIG. 3 illustrates a second embodiment wherein the right release leveris replaced by a nonload-carrying latch member. Load straps 61 and 63engage, respectivelythe left release lever 65 and a support post 67. Theleft release lever is rotatably mounted by pin 69 to support (notshown).

The right release latch 71 is similar in design to the lever of thefirst embodiment. However, even though the members 71 and 65 touch at apivot point 73 and the force line which is normal to the rounded end 75of the left lever 65 passes through mounting pin 77 for lever 71, spring79 is necessary to rotate right member 71 clockwise, permittingcounterclockwise rotation of left lever 65.

The locking lever, including its key, hook, and the rotatable mountingtherefor, together with the timer-output shaft and hook-engaging pin areidentical with those disclosed for the first embodiment. Accordingly,these members are identified by the same reference numbers used in FIGS.1 and 2.

A minimal load is transmitted from the left lever 65 to mounting pin 77.The spring 79 is disposed to normally urge locking lever 41 in aclockwise direction, and key 55 into slot 53 as the timer output shaft51 rotates.

The timer used in the release mechanism of this invention may be of anyconventional design incorporating a rotatable output shaft. Thepreferred embodiment shown in FIGS. and 6 is a conventional artilleryfuse clock timer having an additional actuating plunger 81 and atransportation locking pin 83 which locks the plunger 81 by passingthrough groove 85 to engage hole 87.

- Timing mechanism 89 includes a conventional escapement spring 92 andlever 93 which carry pallets 91 which engages the escape wheel 95 asshown generally in FIGS. 4 and 6. The start-stop lever 97 is pivotallymounted in mechanism 89 and biased by return spring 99. Lever 97 carriesa spring 101 with a hook formed on the end which engages escape lever 93and causes a pallet 91 to engage the teeth of escape wheel 95, causingthe timer gear train 96 to stop.

The timer of FIGS. 5 and 6 is driven by mainspring 103 which is wound byrotation of knob 105. Knob 105, mainspring 103, and gear 107 are rigidlyattached to timer output shaft 51. Gear 107 meshes with the gear train96 of timing mechanism 89 as shown in FIG. 6.

To stop the timer of FIGS. 4 and 5, plunger 81 is depressed againstspring 111 rotating lever 97 against return spring 99 and therebylocking lever 93 and pallet 91 in escape wheel 95. Key 83 is theninserted through hole 87 to lock the timer.

To use the timer knob 105 is rotated clockwise as shown in FIG. 6'untilthe desired time, as indicated on the dial 110 carried by knob 105 liesbeyond arrow 113. The timer is allowed to run until the desired timedelay is aligned with arrow 113. Rotation of the knob 105 to set thetimer also winds mainspring 103. v

Setting. clutch 114 allows gear train 96 to rachet during settingthrough elongated pivot hole 1 16 in back plate 1 18 and restrainingspring 120 mounted on plate 122. The action of the spring 120 againstshaft 124 as shown in FIG. 6 permits setting of the timer withoutdriving the gear train 96 backward.

Plunger 81 is then depressed and key 83 is inserted to lock the timer.Removal of key 83 will then start the timer which will rotate outputshaft 51 under control of the escapement until slot 53 registers on key55 at which point the release levers 13 and 23 will release the load asshown in FIG. 2.

In summary, this invention provides an accurate and dependable timedelay release mechanism adapted to release large loads without stalling.Two embodiments are disclosed, the first utilizing two release leverseach engaging a load, and in a second, a single, loaded release lever.

A mechanical timer has also been described which is adapted to drive aslotted output shaft. Many well-known timers, both mechanical andelectrical, can be adapted to drive the said shaft in the mannerdisclosed provided they have a start-stop capability. The releasemechanism of this invention will function even though the timer used hasa very weak output because there is no surge requirement for releasingthe load at the expiration of the preset time. Accordingly, thisinvention is not limited to the particular timer disclosed, butcomprehends any conventional timer which may be adapted to thisinvention utilizing principals well known in the art.

It is further disclosed that the invention is used to release largeloads held by steel banding straps. However, the release mechanism ofthis invention is not intended to be limited to releasing straps. Thisinvention is intended to be used with any type of load which can beapplied to the release lever or levers in the manner herein described.

It will be obvious to those skilled in the art that a variety of designmodifications are possible within the scope of this invention. Therelease mechanisms herein disclosed are preferred embodiments of thisinvention and the description thereof not intended to exclude obviousdesign modifications.

What is desired to be secured by US. Letters Patent is claimed asfollows:

1. A settable time-delay release mechanism for restraining and releasingextremely large loads comprising:

a. A first release lever rotatably connected to a support at an endthereof, said first lever including a load-engaging portion at an endadjacent the mounting and a pivot at an end opposite the connection;

. A second release lever disposed adjacent said first lever, androtatably connected to a support at an end thereof, said second leverhaving a load-engaging portion at an end thereof adjacent saidconnection, a pivot portion for engaging the pivot portion of said firstlever, and a lockengaging portion;

. Time-delay locking means for engaging the locking portion of saidsecond lever when the pivot portion of said second lever engages thepivot portion of said first lever, and for subsequently releasing saidlever; so that when said first lever engages a load and said secondlever engages a load said locking means holds said levers in adjacentdisposition at the pivot portions thereof for a preset time, and thenreleases said levers for rotation, releasing the said loads.

2. The release mechanism of claim 1 wherein said first lever includes aload-engaging hook disposed at the rotatable support connection and anelongated lever arm having, distally thereto, a rounded pivot portion;so that when said lever engages a load, said load normally urgesrotation of said lever to release said load; and when the pivot portionof said first lever engages the pivot portion of said second lever, saidsecond lever prevents rotation of said first lever.

3. The release mechanism of claim 2, wherein said second release leverincludes a load-engaging hook disposed at the rotatable supportconnection; a pivot portion disposed adjacent the rotatable supportconnection for engaging the pivot portion of said first lever; and anelongated lever arm terminating in a lock-engaging portion, so that whensaid hook engages a load, said load normally urges said lever intorotation about the support connection to release said load, and whensaid locking means engages the locking portion of said lever arrn saidlocking means prevents rotation of said release lever.

4. The release mechanism of claim 3 wherein said timedelay locking meanscomprises:

a. A locking member rotatably connected to a support at an end thereofand carrying a lever-engaging hook at an end opposite the rotatablesupport connection; so that when said second release lever engages aload, and said member engages said release lever, said lever normallyurges said member into rotation about said support connection todisengage the hook and said release lever;

. Timer means disposed adjacent said locking member for preventingrotation of said locking member for a preset time and for allowingrotation of said locking member to release said second lever so thatwhen said timer allows rotation of said locking member the hook releasessaid second lever for rotation and said second lever releases said firstlever for rotation, said levers releasing the loads.

5. Time-delay locking means of claim 4 wherein the timer means includesa rotatable output shaft having a slot therein, and the locking meanscarries a key, said key adapted to normally ride on said shaft as saidshaft rotates until said key registers on the slot, said second releaselever normally urging said key into said slot for rotational movement ofsaid locking member to release said second lever.

6. In a time-delay release mechanism including means for engaging aload, a settable timing means, and locking means for releasably lockinga load in said load-engaging means, and for unlocking said load-engagingmeans releasing the load responsive to the expiration of a preset time,the improvement comprising:

a. A rotatable output shaft driven by said timing means, said shafthaving a key receiving slot;

b. A key carried by said locking means and disposed to ride on saidshaft, said load engaging means normally urging said key against saidshaft when said locking means is looking a load in said engaging mans;said key adapted to enter said slot and unlock said locking means whensaid key registers on said slot.

7. The release mechanism of claim 6 wherein'the load engaging meanscomprises:

a. An elongated lever rotatably connected to a support, a tan endthereof, said lever having a load-engaging hook adjacent said rotationalconnection and a pivot portion at the end opposite said connection;

bl A biased latch disposed adjacent said lever and rotatably connectedat an end thereof to a support, said latch having a pivot-engagingportion adjacent said rotational connection and a locking portion at theend opposite said connection; said latch adapted to engage said pivotalportion of said lever and releasably engage said locking means at thelocking portion thereof so that when said lever hook engages a load saidlatch connects said lever and said locking means until said lockingmeans releases said latch.

8. The release mechanism of claim 6 wherein the settable timing meanscomprises:

a. A main spring attached to said output shaft, said mainspringrotatably driving said shaft;

b. An escape wheel drivingly connected to said output shaft,

distally to the key receiving slot;

0. Pallet means for selectively engaging said escape wheel and forregulating the advance of said wheel responsive to the drive of saidmainspring;

d. Timer locking means for selectively engaging said pallet means tostop the advancement of said wheel and the rotation of said outputshaft.

9. The timing means of claim 8 wherein the timer-locking meanscomprises:

a. A biased lever disposed adjacent said pallet means;

b. Resilient arresting means operably connected to said lever at an endthereof for selectively engaging said pallet means to arrest theadvancement of said escape wheel responsive to the displacement of theend of said lever.

10. The locking means of claim 9 wherein said lever is a bellcrank withan end thereof operably engaging said arresting means, and said lockingmeans further comprises a biased plunger pivotally connected to saidcrank at an end thereof opposite said arresting means whereby depressionof said plunger displaces the end of said crank engaging said arrestingmeans and said pallet and release of said plunger releases said pallet.

11. The release mechanism of claim 6 further comprising a settable,graduated indicator means disposed adjacent the key receiving slot onsaid output shaft for indicating the length of time necessary for saidshaft to rotate until said key enters said slot releasing said load.

1. A settable time-delay release mechanism for restraining and releasingextremely large loads comprising: a. A first release lever rotatablyconnected to a support at an end thereof, said first lever including aload-engaging portion at an end adjacent the mounting and a pivot at anend opposite the connection; b. A second release lever disposed adjacentsaid first lever, and rotatably connected to a support at an endthereof, said second lever having a load-engaging portion at an endthereof adjacent said connection, a pivot portion for engaging the pivotportion of said first lever, and a lock-engaging portion; c. Time-delaylocking means for engaging the locking portion of said second lever whenthe pivot portion of said second lever engages the pivot portion of saidfirst lever, and for subsequently releasing said lever; so that whensaid first lever engages a load and said second lever engages a loadsaid locking means holds said levers in adjacent disposition at thepivot portions thereof for a preset time, and then releases said leversfor rotation, releasing the said loads.
 2. The release mechanism ofclaim 1 wherein said first lever includes a load-engaging hook disposedat the rotatable support connection and an elongated lever arm having,distally thereto, a rounded pivot portion; so that when said leverengages a load, said load normally urges rotation of said lever torelease said load; and when the pivot portion of said first leverengages the pivot portion of said second lever, said second leverprevents rotation of said first lever.
 3. The release mechanism of claim2, wherein said second release lever includes a load-engaging hookdisposed at the rotatable support connection; a pivot portion disposedadjacent the rotatable support connection for engaging the pivot portionof said first lever; and an elongated lever arm terminating in alock-engaging portIon, so that when said hook engages a load, said loadnormally urges said lever into rotation about the support connection torelease said load, and when said locking means engages the lockingportion of said lever arm said locking means prevents rotation of saidrelease lever.
 4. The release mechanism of claim 3 wherein saidtime-delay locking means comprises: a. A locking member rotatablyconnected to a support at an end thereof and carrying a lever-engaginghook at an end opposite the rotatable support connection; so that whensaid second release lever engages a load, and said member engages saidrelease lever, said lever normally urges said member into rotation aboutsaid support connection to disengage the hook and said release lever; b.Timer means disposed adjacent said locking member for preventingrotation of said locking member for a preset time and for allowingrotation of said locking member to release said second lever so thatwhen said timer allows rotation of said locking member the hook releasessaid second lever for rotation and said second lever releases said firstlever for rotation, said levers releasing the loads.
 5. Time-delaylocking means of claim 4 wherein the timer means includes a rotatableoutput shaft having a slot therein, and the locking means carries a key,said key adapted to normally ride on said shaft as said shaft rotatesuntil said key registers on the slot, said second release lever normallyurging said key into said slot for rotational movement of said lockingmember to release said second lever.
 6. In a time-delay releasemechanism including means for engaging a load, a settable timing means,and locking means for releasably locking a load in said load-engagingmeans, and for unlocking said load-engaging means releasing the loadresponsive to the expiration of a preset time, the improvementcomprising: a. A rotatable output shaft driven by said timing means,said shaft having a key receiving slot; b. A key carried by said lockingmeans and disposed to ride on said shaft, said load engaging meansnormally urging said key against said shaft when said locking means islocking a load in said engaging mans; said key adapted to enter saidslot and unlock said locking means when said key registers on said slot.7. The release mechanism of claim 6 wherein the load engaging meanscomprises: a. An elongated lever rotatably connected to a support, a tanend thereof, said lever having a load-engaging hook adjacent saidrotational connection and a pivot portion at the end opposite saidconnection; b. A biased latch disposed adjacent said lever and rotatablyconnected at an end thereof to a support, said latch having apivot-engaging portion adjacent said rotational connection and a lockingportion at the end opposite said connection; said latch adapted toengage said pivotal portion of said lever and releasably engage saidlocking means at the locking portion thereof so that when said leverhook engages a load said latch connects said lever and said lockingmeans until said locking means releases said latch.
 8. The releasemechanism of claim 6 wherein the settable timing means comprises: a. Amain spring attached to said output shaft, said mainspring rotatablydriving said shaft; b. An escape wheel drivingly connected to saidoutput shaft, distally to the key receiving slot; c. Pallet means forselectively engaging said escape wheel and for regulating the advance ofsaid wheel responsive to the drive of said mainspring; d. Timer lockingmeans for selectively engaging said pallet means to stop the advancementof said wheel and the rotation of said output shaft.
 9. The timing meansof claim 8 wherein the timer-locking means comprises: a. A biased leverdisposed adjacent said pallet means; b. Resilient arresting meansoperably connected to said lever at an end thereof for selectivelyengaging said pallet means to arrest the advancement of said Escapewheel responsive to the displacement of the end of said lever.
 10. Thelocking means of claim 9 wherein said lever is a bellcrank with an endthereof operably engaging said arresting means, and said locking meansfurther comprises a biased plunger pivotally connected to said crank atan end thereof opposite said arresting means whereby depression of saidplunger displaces the end of said crank engaging said arresting meansand said pallet and release of said plunger releases said pallet. 11.The release mechanism of claim 6 further comprising a settable,graduated indicator means disposed adjacent the key receiving slot onsaid output shaft for indicating the length of time necessary for saidshaft to rotate until said key enters said slot releasing said load.